Cylinder lock



Patented Des. B, 1931 PATENTS OFFICE FRANK E. IIOMPSON AND ALFRED 'LAWRECE, OIE STAMFORD, CONNECTICUT, ASSIGNORS TO THE YALCE & TOWNE MANUFACIIRING COMPANY, 025 STAMFORD,

CYLINDZR LOOK Application fi1ed Ma 27, 927; S1ial No. 194,722.

This invention relates to improvements in oyhnder look structures and more part1ou larly to means for insuring the proper norl 1s 111 looked position, and thus passage of mal use and operation of the key.

In pin tumblerlocks, improper operation of a key is sometimes possible due tothe fact that the key is not fully inserted, the pins then being allowed to ride on the slopes instead of in the depressions of the key.

Objeots of the .present invention are to prevent error in the insertion of a key into a pin turnbler look; to render normal complote insertion of the key neoessary to the operation of the look, and to provide simple and efiioient means whioh shall be operable to insure full insertion of the key into the look before the ,plug oan be turned t0 eieot oporation of the look.

Vith these and other objeots in view, the invention oonsists in certain novel eatures as hereinafter set forth and pointed out in the olaims.

In the aocompanying drawingsz- Figure 1 is a view illustrating-our improvements Figllre 2 is an enlarged transverse sectional view Figure 3 is an enlarged transverse sectional view showing the look oylinder and the plug oavity therein;

Figure 4 is a transverse sectional view of the plug;

Figure 5 is a detail view of the Ushaped momber, and

Figure 6 is a dotail view of thekey.

In the drawings, a look oylinder is represented at 1, and is made with a oavity or bore 2 for the accommodation of the plug member 3 of the look, but the pin tumbler n1eohanism has boen onntted as a deta1l show- 1ng of the same in the draw1ng 1s not deemed ossential to an understanding of the present invention. J

The plug 3 is provided with' the usual key slot 4 and near one end the Plug is made with transvorselydisposed sookets or bores 5, 5 disposed at respective sides o f the key slot 4 for the reoeption of the parallel arms of a U-shaped member 6 whioh spansthe key 7 when the latter is in the plug 3. The

wall of the plug bore in the oylinder is made with a depression8 into Whioh the U-shaped inelmber 6 enterS when the plug the key into the plug is permitted. If the key be provided with a'nOtch or reoess 9 oor+ 'member 6 will ride into suoh notoh upon the turnin% of the key pliig. If the notoh is incorrect serted, the U-member Will of course prevent operation of the look by wedging'in betweon the key and the oylihder.

Heretofore, it has been the oustom to foim the forward end of the key 7 relatively blunt, but with a key thus formed,ithas been found that itmaybe improperly operated at timeS by inoompletely inserting the key sothat the pi1i tumblers will ride on the slopes of the key rather than in the depressions. In aooordanoe with the present invention, the forward end of thekey isout aWay sliarply from its No. 1 bitting as indicated at 1IFigure 1, sothat if the proper key is notfully inserted or a key of a slightly' diferent contour is but partially inserted, t oonsiderable drop of the N o. 1 pin Will be obtained and the look secured against operation. The proper key must, therefore, be employed and it must be fully inserted t0 insure 1ts properoperatio1i in effeoting the turning of the plug member of from a bittingothor than bitting No. 1, and under certain ciroumstanoes it might be ad visable to have a shaip rise from a bitting i11- stead of a drop. Any definite change in key contour whereby a oonsiderable pin movement is obtained by only a slight key movement, is within the soope of this invention. By provision of the improvements embodying the movable U-shaped member and its oooperation with the plug, oylinder and y placed or the key is not fully in key, complote insertion of the key Will be insured.

It Will be observed that the key c0nstruotion hereinbefore desoribed Will serve t0 prevent sl1ght error in key insertion and the use of the U-member as previously desoribed Wlll' L ioo We claim as new and desire to seure by Lettors-Patent, is

1. In a pin-tumbler look meehmism, a plug having a key 5101; and transverse bores al; respective sides of the key slot, a U-shaped member having its pnrallel arms freely enter v v ing sa1d transverse bores, a oyl1nder ha.v1ng

a recess to receive said U-shaped member and permit insertion of a key into the key slot in the plug, the key having a reoess to receivethe cross bar of said U-shaped member.

2. In a pin tumbler look, et U wedging member mounted in alined recesses of the plug and cylinder When the look is in locked position, sad U member being adapted to be cammed entirely into the plug recess open 7 slight movement of the plug in order to per.

mit full moement thereof, the key of said look being slotted to permit th-is necessary movement.

3. In a pin tunbler look .having alined reeesses in the plug and cylinder, L U member having its vertical arms norfnally in the plug 1-ecesS and its horizontal member in the eylinder reeess, said look beng Operable by a slotted key, sa:id horizontal member being dapted to cam upwardly into said key slot and plug recess upon opemtion of the look.

4. In a pin tumbler look including a plg and eylinder, a. U-shaped member mounted to operate in alined recesses of the plug and cylinder, said 'U-member being adapted to be cammed entirely into the plug recess upon opemtiori of the look, thekey for the look being slotted t0 permit such camming movement so as to render possible look operati0n.

In testimony whereof, We have signed this specification.

' FRANK E. THOMPSON. r

ALFRED LAWRENCE; 

